Electrical precipitator



May 17, 1949. K. w. MacKENzlE 2,470,356

l l ELECTRICAL PRECIPITATOR Filed June 2o, 194e Sheng-sheet 1 TTY May 17, 1949. 'K. wfMacKENzlE 2,470,356

ELECTRICAL PRECIPIT/ATOR Patented May 17, 1949 iMass., assigner to Raytheon"Manufacturingf Company, Newton, Massa, ai corporationiof Delaware Application Jlunetzo, 1946,,s'erri1 No. '6778,146,

46` Claims. (019183-7) "This invention relates to electrical-precipitators` -for electrically precipitatingdust orsmloke fromatmsphericair flue gases orithe like@ VMore particularly, vthe invention relates to precipitajtor's of'the type in which theairrorthe-other gas ,"to be 'cleanediis first ionized by anionizing devi-ce and thereafter 'passedI 'through a precipitating *device comprising` `a plurality -ofparallel` plates, falter-nate platesbeing charged inone polarity and "intervening plates charged in the; opposite ff'pol'arity. The invention is primarily .concerned A`With the constructien"4 and"arrangerner'it ofthe precipitatingdevice; In precipitatorsvof the typek to whichtheing vention relates the constructionof theprecipita-l "lftorfchamber involves a number of-difrloult-mainj"`ufactu`ring problems, Alargenurnber ofp-lates 'inust beasse-mbled and supported in spaced 'par- "allelrelation",v with any ltwio'suecessiveplatesinffsulated from each other, so that alternate plates A `of "the structure maybechargedin one-polarity and the intervening plates ychargedfinthe opposite polarity or grounded. Heretoiorathefconfstructinlof'such devices hasinvolved elaborate welding or brazing operations inl :the assembly of fthe plates or has required the provision-'- ofnumerous'insulators 'between the plates for the purf `pose of spacing and'supportingjthem.- vIt is among the objects of the -inventionto -pro "f may be readily assernbled'fbyA a simple stacking ff "operation- Without kneoessitating a large number "fof =vvelding operations andvvithout requiringhthe "insertion Iof spaced insulators between the plates.

A"fur'th`er object -ofV the V invention 'isA to provide a rigid f and firmly connected structure in which fthe ground plate .assembly isZ directlyy supported "bya pair of' side'plates forming thelouter yside fwalls of the assembly and in'which the charge l plates are supported in the `proper spaced `par,-

' vvalls yt-insulated therefrom.' "A'f'further robject' of the 'invention isv to provide acons'tructionfin whichthe ground plates:l may be-adjusted relative tot'he'fcharge plates.

The above* and l other objects and featuresl ofA the Yinventionv will fbe made fully apparent `tovthose skilled in the art from aconsid-eration of the fol- 'lowing detailed decsripton taken in conjunction jwiththe accompanying drawings, in whichu Fig. 1l shows a front elevation of 'a'precipitator chamber `constructed in 'accordance with the-*inside elevation,

taken on me une 2-2 of Fig. 1

" precipitator; and" 231; Fig. 3` shows a side e1 vation;ofjthelprecipi- 'tatori Figfl is a detail,showing1 the constructioniof 'one' off the ground 'plates of fthe: "precipiifa.;y ,f

5 is alview similarftoFig.,4showing' the construction of onefof' the 'chargeyplatesofthe 'Fg1`6 shows oneY of'fa pairofichargerplates jwhich4 are; of slightly modified'epnstruenon:or 1o supportingthel charge plate' assembly. y l n Referring @to the drawings. the* precipitator lchamber'-oorrlprises a pair] ofsidev Wallsfjl lliandd I, which side Walls are groundfed"a'rid'pro l"the v's'ole'sllipport for, a plurality of' preoipitatowplates Alternate of said precipitatorplates 1I2,'"h ein V iter4 called the groundlplates, are support-,eddireetly'vfro-rn the side Walls-I Il 'andjI I' an'dgieleetrifcally'connectedtheretonin a liriztrirler tofbe more 'fully' A described vIliterveningf plates vI 3; hereinafter called charge plates; lare alsol Su'p'por the side wang 1| oand i| :but insulated( relative thereto" and to the groundplates,v IIZ'iIia mann-er u tobe described.'

In `order to v*support the groundplates I 2`l in spaced' parallel" relation to the'sdfW-alls Illl and I-I,` andt'of each-other, six tie1rods"`l flISi'jh'a'vi'ng "srewethreaded-- end portions extending A through `fvidea precipirtatorfof the typedescribed' which.

'theretoby nuts-Zilarid 2I"p'ositioned A outside of the side Walls tof, the casingiandjrigidly securing 4jsfaid *tie rods' thereti 'plurfalityJ of l spacing bushings '2-2, onej on each tierod-4 between vleach' "off` thel successive j'pla'tes'f -I2 ;fmai1itain1 "said plates' in theproper :spaced rela/tion, and nuts 23,

one adjacent each end 1 ofeach offth tie-"rods y' Ill-I S'betweerr the outermost-oftheplates I-2-'afnd theside wallsfllleandfll, preventlateralimotlon ,ffSa-d-p1atesll2f. .f :f 1-

. 40 Z""'allel 'relati'onto the ground'plates from'saidiside vIn order tosupport theicharge-plates I-3iinpar allel spaced relationftothe groundplates+2; and

`*insulated :therefrom and relative Vto the side'iwalls mA and M aseeond seeof ne'- rossi-comprising five tie rods 24 :to 2,`y inclusive;bfi'sllghtlyeless length' than the y length of' 'the ods "it-rl 9; carry the'- plates I3 in spa-cedparallelirelation Withone "of 'the' plates I Sbetween arytyvofsuccessiveplates I2? The plates 3a1'e 'SpCedby'*bushihgsliin the same manner-*in Which-.the plates '-I`2 ar separated by; theI spacing bushings '2li The 'rendsof `the; tie rods 24i--28' arefscrevv threaded; and'nuts 29; one on eacniendbfeach of"sai'i""ti rods;" `serure `fthe`A charge 4plate structure ltogether; ""1- Openings 3|;35, in each ofjthefside'walllsl and I I, provide an" insulating `-clearancelsiiaoe'a Ibethe plates I3.

. of the spacing bushings 3B.

3 side walls. Similarly spaced openings 3I-35' in eac-h of the plates I2, which openings are of substantially larger diameter than the external diameter of the spacing bushings 3l), provide an insulating space between the ground plates I2 and the spacing bushings 30 of the 'plates I3. Openings 3ft-Hin the plates I2 have a suilicient diameter to per-mit the -rods Inl-I9 to pass therethrough, but are of substantially less diameter than the spacing bushings 22 on the tie rods III-I9, so that the spacing bushings secure the plates I2 therebetween at ea-ch of said openings 31E-4I. The charge plates I3 are of slightly less length than the plates I2 and are provided with cut-away portions l2 and 43 at the upper ends thereof, openings dll and 45 in the central portion thereof, yand cut-away porti-ons 66 and lil at .their lower ends, which cut-away portions and openings provide a clearance for the rods iii-I9 kand the bushings 22 at the points where these rods and bushings pass adjacent to -or through Gpenings dt-52 in each of the plates I3 are provided for the rods 2li-28, respectively, these openings being of suicient diameter to permit the rods to pass therethrough `and of substantially less diameter than the diameter Each of Ithe plates I3 is thus secured on each side thereof between two of the Spacing bushings 3Q at each of the openings llt-52, except Ithe outermost of said plates, which are secured adjacent the side walls I and I I by the nuts 29.

Two of the charge plates, intermediate the length of the precipitator chamber and indicated at I 3', have projecting corner portions 53 provid-y ing tabs for securing the plates I3 to insulators 54. The insulators d are secured by nuts 55 to the projecting tabs of the plates I3 and by nuts 56 to the side walls Ill and II of the precipitator. Otherwise the plates I3 conform in contour to plates I3 and are provided with cut-away portions of openings 42-52 corresponding to the cut-away portions and openings of the plate I3.

By the construction described in the foregoing, the precipitator plates can be assembled by a simple stacking process in which the charge plates and the ground plates are alternately stacked on the tie rods with the spacing bushings 30 positioned between successive charge plates and spacing bushings 22 between successive ground plates. By this construction there is complete electrical spacing of the ground plate assembly from the charge plate assembly without the necessity of utilizing insulating spacers therebetween, the openings and cut-away portions in the Vprecipitator plates permitting a substantial clearance between the supporting rods and spacing bushings of the oppositely charged plates to provide a substantial insulating space therebe- V tween. The relatively few insulators required to support the charge plate assembly in spaced in- 44sulated relation to the ground plate assembly vtor structure constitutes a rigid unitary assembly supported entirely by the outer side walls I and II, and this assembly may be readily inserted as a unit in a complete electrical precipitator assembly.

It will be understood that the precipitator chamber shown is adapted to be used in conjunction with a suitable ionizing device for ionizing the air or gases to be cleaned prior to the flow thereof through the spaces between the precipitator plates. A suitable ionizing device is described and claimed in my copending application Serial No. 678,145, filed June 20, 1946.

While there has been herein described a preferred embodiment of the invention, other embodiments within the scope of the appended claims will be apparent to those skilled in the art from a consideration of the form shown and the teachings hereof.

What is claimed is:

1. A precipitating device for electrical precipitators, comprising a pair of side walls forming the end walls of said precipitating device, a plurality of dust precipitating plates positioned parallel to said side walls and to each other, al

plurality of tie rods extending from one of said side walls to the other and rigidly secured and electrically connected thereto, alternate of said plates providing ground plates and being supported by said tie rods, spacing bushings on said tie rods, one on each of said tie rods between any pair of successive alternate plates, a second set of tie rods extending through cut-away portions and openings in said alternate plates and free from said side walls, the dust precipitating plates intervening said alternate plates and providing charge plates being mounted on said second set of tie rods, spacing bushings on said second set of tie rods one on each of said tie rods between any pair of successive charge plates, and insulators secured to said side walls and two of said charge plates for supporting all of said charge plates from said side walls in spaced relation to said alternate plates.

2. A precipitating device for electrical precipitators, comprising a pair of side walls forming the end walls of said precipitating device, a plurality of dust precipitating plates positioned parallel to said side walls and to each other, a plurality of tie rods extending from one of said side walls to the other and rigidly secured and electrically connected thereto, alternate of said plates providing ground plates and being supported by said tie rods, spacing bushings on said tie rods, one on each of said tie rods between any pair of successive alternate plates, a second set of tie rods extending through cut-away portions and openings in said alternate plates and free from said side walls, the dust precipitating plates intervening said alternate plates and providing charge plates being mounted on said second set of tie rods, spacing bushings on said second set of tie rods one on each of said tie rods between any pair of succesive charge plates, two of said charge plates having projecting portions, and insulators secured to said side walls and to said projecting portions of said two of said charge plates for supporting all of said charge plates from said side walls in spaced relation to said alternate plates.

3. A precipitating device for electrical precipitators, comprising a pair of side walls forming the end walls of said precipitating device, a plurality of dust precipitating plates positioned parallel to said side walls and to each other, a plurality oi tie rods extending from one oi said side walls to the other and rigidly secured and electrically connected thereto, alternate of said plates providing ground plates and being supported by said tie rods, spacing bushings on said tie rods, one on each of said tie rods between any pair of successive alternate plates, a second set of tie rods extending through cut-away portions and openings in said alternate plates and free from said side walls, the dust precipitating plates intervening said alternate plates and providing charge plates being mounted on said second set of tie rods, spacing bushings on said second set of tie rods one on each of said tie rods between any pair of successive charge plates, two of said charge plates having projecting portions, insulators secured to said side walls and to said projecting portions oi said two oi said charge plates for supporting all of said charge plates from said side walls in spaced relation to said alternate plates, and means for adjusting said ground plates relative to said charge plates.

4, A precipitating device for electrical precipitators comprising a pair of side walls forming the end walls of said precipitating device, a plurality oi dust precipitating plates positioned parallel to said side walls and to each other alternate of said plates constituting ground plates, and the intervening plates constituting charge plates, a first set of tie rods rigidly secured and electrically connected to said side walls, said tie rods passing through openings in each of said ground plates whereby said ground plates rest on and are supported by said iirst set of rods at said openings, means on said nrst set of tie rods for maintaining said ground plates in spaced relation and preventing displacement thereof relative to said rods, a second set of tie rods extending across the space between said side walls and free from electrical contact therewith, said second set of tie rods passing through openings in each of said charge plates and being in electrical contact with said charge plates at said openings, means on said second set of tie rods for maintaining said charge plates in spaced relation and preventing displacement thereof relative to said second set of rods, said ground plates each having relatively large openings through which said second set of tie rods pass with a substantial clearance therebetween, said charge plates having openings through which said first set of tie rods pass with a substantial clearance therebetween, a plurality of insulators secured to said side walls, and means supporting two of said charge plates by said insulators whereby said two plates support said second set of tie rods and thereby support the remainder of said charge plates.

5. A precipitating device for electrical precipitators comprising a pair of side walls forming the end walls of said precipitating device, a plurality of dust precipitating plates positioned parallel to said side walls and to each other alternate of said plates constituting ground plates, and the intervening plates constituting charge plates, a rst set of tie rods rigidly secured and electrically connected to said side walls, said tie rods passing through openings in each of said ground plates whereby said ground plates rest on and are supported by said rst set of rods at said openings, means on said first set of tie rods for maintaining said ground plates in spaced relation and preventing displacement thereof relative to said rods, a second set of tie rods extending across the space between said side walls and free from electrical contact therewith, said second set of tie rods passing through openings in each of said charge plates and being in electrical contact with said charge plates at said openings, means on said second set of tie rods for maintaining said charge plates in spaced relation and preventing displacement thereof relative to said second set oi rods, said ground plates each having relatively large openings through which said second set of tie rods pass with a substantial clearance therebetween, said charge piates having openings through which said first set of tie rods pass with a substantial clearance therebetween, a plurality oi insulators secured to said side walls. means supporting two oi said charge plates by said insulators whereby said two plates support said second set of tie rods and thereby support the remainder of said charge plates, and means for adjusting the spacing of said ground plates relative to said charge plates.

6. A precipitating device for electrical precipitators comprising a pair of side walls forming the end walls of said precipitating device, a plurality of dust precipitating plates positioned parallel to said side walls and to each other a1- ternate of said plates constituting ground plates, and the intervening plates constituting charge plates, a rst set of tie rods rigidly secured and electrically connected to said side Walls, said tie rods passing through openings in each of said ground plates whereby said ground plates res-t on and are supported by said nrst set of rods at said openings, metallic bushings on said first set of tie rods for maintaining said ground plates in spaced relation and preventing displacement thereof relative to said rods, a second set of tie rods extending across the space between said side walls and free from electrical contact therewith, said second set of tie rods passing through openings in each of said charge plates and being in electrical contact with said charge plates at said openings, metallic bushings on said second set of tie rods for maintaining said charge plates in spaced relation and preventing displacement thereof relative to said second set of rods, said ground plates each having relatively large openings through which said second set of tie rods pass providing a substantial clearance between the bushings on said rods and said ground plates, said charge plates having openings through which said rst set of tie rods pass with a substantial clearance between the bushings on said second set of rods and said charge plates, a plurality of insulators secured to said side walls, and means supporting two of said charge plates by said insulators whereby said two plates support said second set of tie rods and thereby support the remainder of said charge plates.

KENNETH W. MACKEN ZIE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,344,330 Bradley June 22, 1920 1,573,376 Dickerson Feb. 16, 1926 2,195,431 Shively et al. Apr. 2, 1940 2,380,992 Pegg et al. Aug. 7, 1945 

